Epoxy reactive diluent and manufacturing method therefor

ABSTRACT

Provided is an epoxy reactive diluent, wherein the content of a compound represented by Formula 1 below is 85% by weight or more based on a total weight of an epoxy reactive diluent composition: 
     
       
         
         
             
             
         
       
     
     wherein n is 0, 2, 4 or 6.

TECHNICAL FIELD

The present invention relates to an epoxy reactive diluent and a methodof preparing the same, and more particularly to an epoxy reactivediluent including epoxidized cardanol and a method of preparing thesame.

BACKGROUND ART

Conventionally, various components including epoxy components such asbenzyl glycidyl ether, n-butyl glycidyl ether, phenyl glycidyl ether,o-cresyl glycidyl ether, aliphatic glycidyl ether, etc. have been addedas plasticizers and diluents for epoxy paint. Such components, which areadded as reactive diluents to epoxy paint, have been used to impartplasticity or adjust pot-life.

Thereamong, epoxidized cardanol, i.e., cardanol glycidyl ether, producedusing cardanol as a raw material extracted from natural cashew nuts hasan epoxy functional group in a molecular structure thereof, therebybeing capable of providing excellent film properties during thehardening reaction of epoxy paint. In addition, unsaturated hydrocarbonchains of cardanol can facilitate crosslinking, thereby being capable ofimproving the strength, flexibility and heat resistance of a film. Thestructure of epoxidized cardanol is shown in Formula 1 below:

wherein Formula 1, n is 0, 2, 4 or 6.

FIG. 1 illustrates a method of extracting a cardanol raw material fromcashew nuts. Cardanol extracted by such a method has a hydrocarbon chainat a meta position of a phenolic hydroxy group thereof. Epoxidizedcardanol can be obtained by reacting cardanol with epicholorhydrin inthe presence of an alkylation catalyst. This reaction has beenconventionally performed in the presence of an aqueous solution or adimethyl sulfoxide solvent. In addition, a base such as sodiumhydroxide, potassium hydroxide, sodium carbonate, potassium carbonate,sodium hydride, etc. has been used as a catalyst, and a phase transfercatalyst such as tetra-n-butylammonium chloride, etc. as a subcatalystfor reaction activation has been added. After completion of thereaction, epoxidized cardanol was extracted using an organic solvent,and reaction byproducts were removed through a washing process so as toimprove the purity of a diluent.

Nevertheless, existing technologies have problems that the purity of adesired product, epoxidized cardanol, is low due to the high content ofreaction byproducts, and it is difficult to treat wastewater generatedin an extraction process using an organic solvent. In addition, in thecase of some technologies, products may be hydrolyzed due to a longreaction time, and thus reaction byproducts increase, resulting inincreases in viscosity and epoxy equivalent weight.

DISCLOSURE Technical Problem

Therefore, the present invention has been made in view of the aboveproblems, and it is one object of the present invention to provide anepoxy reactive diluent having high purity and low viscosity and a lowepoxy equivalent weight through minimization of hydrolysis and sidereactions and a method of preparing the same.

It is another object of the present invention to provide a method ofpreparing an epoxy reactive diluent that is extracted without use of anorganic solvent and thus does not require a washing process causingwaste water.

Technical Solution

In accordance with an aspect of the present invention, the above andother objects can be accomplished by the provision of an epoxy reactivediluent, wherein a content of a compound represented by Formula 1 belowis 85% by weight or more based on a total weight of an epoxy reactivediluent composition:

wherein n is 0, 2, 4 or 6.

In an embodiment, contents of cardanol, a compound represented byFormula 2 below, a compound represented by Formula 3 below, and acompound represented by Formula 4 below in the composition may berespectively less than 2% by weight, less than 5% by weight, less than5% by weight, and less than 4% by weight:

wherein, Formulas 2 to 4, n is 0, 2, 4 or 6.

In an embodiment, the composition may have a viscosity of 40 to 90 cpsat 25° C.

In accordance with another aspect of the present invention, there isprovided a method of preparing an epoxy reactive diluent, the methodincluding: (a) a step of reacting a mixture including cardanol andepicholorhydrin in a presence of a catalyst to obtain a product in whicha content of epoxidized cardanol is 85% by weight or more; and (b) astep of isolating and purifying the product.

In an embodiment, the catalyst may be a base.

In an embodiment, the base may be one selected from the group consistingof NaOH, KOH, Na₂CO₃, K₂CO₃, NaH and a combination of two or morethereof.

In an embodiment, the base may be a 1 to 60% by weight aqueous solution.

In an embodiment, in step (a), the catalyst may be added dropwise to themixture for 45 to 135 minutes, followed by allowing a reaction to occurfor 60 to 180 minutes.

In an embodiment, an equivalent ratio of the cardanol to theepicholorhydrin may be 1:1 to 1:10.

In an embodiment, in step (a), an equivalent ratio of the cardanol tothe catalyst may be 1:0.1 to 1:1.5.

In an embodiment, step (b) may include (b1) a step of filtering theproduct to obtain a filtrate; (b2) a step of separating the filtrateinto an upper layer and a lower layer to remove the lower layer; (b3) astep of vacuum-evaporating the upper layer to recover epicholorhydrin;and (b4) a step of filtering a product generated in thevacuum-evaporating.

In an embodiment, in step (b2), layer separation may be performed byallowing the filtrate to stand for 60 to 180 minutes without addition ofan organic solvent.

In an embodiment, in step (b3), the vacuum-evaporating may be performedat 100 to 120° C.

Advantageous Effects

In accordance with an aspect of the present invention, an epoxy reactivediluent having high purity and low viscosity and a low epoxy equivalentweight through minimization of hydrolysis and side reactions and amethod of preparing the same can be provided.

In accordance with another aspect of the present invention, a method ofpreparing an epoxy reactive diluent that is extracted without use of anorganic solvent and thus does not require a washing process causingwaste water can be provided.

It should be understood that the effects of the present invention arenot limited to the effects described above, but include all effects thatcan be deduced from the detailed description of the present invention orthe constitution of the invention described in the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a method of obtainingcardanol from natural cashew nuts.

FIG. 2 illustrates hydrocarbon chains of epoxidized cardanol preparedaccording to an embodiment of the present invention.

FIG. 3 illustrates an epoxidized cardanol generation reaction accordingto an embodiment of the present invention.

FIG. 4 illustrates a reaction wherein epoxidized cardanol preparedaccording to an embodiment of the present invention is hydrolyzed sothat reaction byproducts are generated.

FIG. 5 illustrates a reaction scheme wherein epoxidized cardanol andreaction byproducts are generated according to an embodiment of thepresent invention.

FIG. 6 illustrates gas chromatography results of a conventional epoxyreactive diluent (a conventional product) and an epoxy reactive diluentprepared according to an embodiment of the present invention.

Modes of the Invention

Exemplary embodiments of the present invention are described in detailwith reference to the accompanying drawings. However, the presentinvention may be implemented in various different forms and is notlimited to these embodiments. To clearly describe the present invention,a part unrelated to the description is omitted in the drawings, and likereference numerals in the specification denote like elements.

In the specification, when it is described that a certain part is“connected” to another part, it should be understood that the certainpart may be directly connected to the other part or indirectly connectedto the other part via another part therebetween. In addition, when acertain part “includes” a certain component, this indicates that thepart may further include another component instead of excluding theother component unless otherwise disclosed.

In the present specification, “reactive diluent” refers to an additiveused to reduce the viscosity of epoxy paint. A reactive diluentparticipates in a hardening reaction during hardening of the epoxy paintto form a portion of a crosslinked structure.

“Plasticity” refers to a deformation property of a material by anexternal force. In the case of materials having low plasticity, crackscan be easily generated even by a weak external force. When the diluentis added to impart plasticity, the flexibility and heat resistance ofthe epoxy paint can be increased.

“Pot-life” refers to the time during which two or more componentsmaintain appropriate fluidity and adhesion without being gelated orhardened. The pot-life of the epoxy paint may be controlled by adjustingthe content of the diluent.

“Epoxy equivalent weight” refers to the weight of a resin including 1equivalent of an epoxy group. The number of epoxy groups in a resindecreases with an increasing epoxy equivalent weight value.

Hereinafter, an embodiment of the present invention is described indetail with reference to the accompanying drawings.

With regard to an epoxy reactive diluent according to an aspect of thepresent invention, the content of a compound represented by Formula 1below may be 85% by weight or more based on a total weight of an epoxyreactive diluent composition:

wherein n may be 0, 2, 4 or 6. C₁₅H₃₁-n chain structures according tothe n value are illustrated in FIG. 2.

The diluent may be added to an epoxy paint to impart plasticity theretoand control the pot-life thereof during a hardening reaction.

FIG. 1 is a schematic diagram illustrating a method of obtainingcardanol from natural cashew nut shells, and FIG. 3 illustrates areaction scheme wherein the compound represented by Formula 1 isgenerated by reacting the cardanol.

In a process of obtaining the cardanol, cardol and 2-methyl cardolby-products represented by Formulas 5 and 6 below may be obtained. Anappearance color of the cardanol may be changed depending upon thecontents of the cardol and the 2-methyl cardol.

Referring to FIG. 3, the compound represented by Formula 1 may beprepared by reacting the cardanol and epicholorhydrin in the presence ofa base. Based on a total weight of the composition, the content of thecompound represented by Formula 1 may be 85% by weight or more, and thecontent of unreacted cardanol may be less than 2% by weight.

FIG. 4 illustrates a reaction scheme wherein the compound represented byFormula 1 is hydrolyzed so that reaction byproducts are generated, andFIG. 5 illustrates a reaction scheme wherein the compound represented byFormula 1 and compounds represented by Formulas 2 to 4 below aregenerated by reacting the cardanol.

Referring to FIG. 4, the compound represented by Formula 1 may be easilyhydrolyzed under a water condition to form 3-cardanoxy-1,2-propanediolas a reaction byproduct, which may increase an epoxy equivalent weightvalue of the composition. When an epoxy equivalent weight valueincreases, hardening reaction characteristics of epoxy paint may bedecreased. Accordingly, the properties of epoxy paint may be increasedby reducing the content of the reaction byproducts.

Based on a total weight of the composition, the contents of cardanol, acompound represented by Formula 2 below, a compound represented byFormula 3 below, and a compound represented by Formula 4 below may berespectively less than 2% by weight, less than 5% by weight, less than5% by weight, and less than 4% by weight:

In Formulas 2 to 4, n may be 0, 2, 4 or 6. A C₁₅H_(31-n) chain structureaccording to the n value may be the same as the compound represented byFormula 1.

The cardanol may be a product which does not react during thepreparation of the composition.

The compound represented by Formula 2 is 2-methyl-cardol glycidyl ether.The compound represented by Formula 3 is cardol-diglycidyl ether. Thecompound represented by Formula 4 is a dimer and may include both thecompounds with different structures shown in Formula 4.

Referring to FIG. 5, the viscosity of the composition increases as thecontents of the compound represented by Formula 2, the compoundrepresented by Formula 3, and the compound represented by Formula 4increase, so that viscosity control characteristics may be decreased.Accordingly, the properties of epoxy paint may be improved by loweringthe contents of the compound represented by Formula 2, the compoundrepresented by Formula 3 and the compound represented by Formula 4. Theviscosity of the composition may be 40 to 90 cps, preferably 40 to 60cps, at 25° C.

The composition may not include organic solvents such as methanol,ethanol, isopropanol, acetone, toluene and dimethyl sulfoxide. When theorganic solvents are included, organic solvent waste water may begenerated in a process of preparing a diluent, resulting inenvironmental pollution.

A method of preparing an epoxy reactive diluent according to anotherembodiment of the present invention may include (a) a step of reacting amixture including cardanol and epicholorhydrin in the presence of acatalyst to obtain a product in which the content of epoxidized cardanolis 85% by weight or more; and (b) a step of isolating and purifying theproduct.

The epicholorhydrin may be used as a reactant and a solvent at the sametime. A product generated by performing the reaction, illustrated inFIG. 3, is hydrolyzed in an aqueous solution and reaction byproducts aregenerated, by a reaction illustrated in FIG. 4, so that an epoxyequivalent weight value of a produced diluent may increase. Addition ofan organic solvent such as dimethyl sulfoxide or methanol may causeenvironmental destruction and an increase in generation amounts of thecompound represented by Formula 2, the compound represented by Formula 3and the compound represented by Formula 4.

The catalyst may be a base. The base may be one selected from the groupconsisting of NaOH, KOH, Na₂CO₃, K₂CO₃, NaH and a combination of two ormore thereof, preferably, NaOH.

The base may be a 1 to 60% by weight aqueous solution, preferably, a 30to 50% by weight aqueous solution. When the concentration of the base isless than 1% by weight, a reaction time increases so that a generationamount of reaction byproducts may increase due to hydrolysis. When theconcentration of the base is greater than 60% by weight, there may be aproblem in controlling a reaction temperature in step (a).

In step (a), the catalyst may be added dropwise to the mixture for 45 to135 minutes, followed by allowing a reaction to occur for 60 to 180minutes. When the catalyst is added dropwise for less than 45 minutes,the temperature of the mixture rapidly increases and thus safetyaccidents may occur. When the catalyst is added dropwise for greaterthan 135 minutes, a generation amount of reaction byproducts mayincrease due to hydrolysis. When the reaction is performed for less than60 minutes, a reaction yield may be decreased. When the reaction isperformed for greater than 180 minutes, the epoxy equivalent weight andviscosity of a produced diluent may excessively increase.

An equivalent ratio of the cardanol to the epicholorhydrin may be 1:1 to1:10, preferably, 1:2 to 1:5. When the equivalent of the epicholorhydrinis less than 1, the content of unreacted cardanol in an obtained productmay increase. When the equivalent of the epicholorhydrin is greater than10, resources for recovering the epicholorhydrin may be excessivelyconsumed.

An equivalent ratio of the cardanol to the catalyst may be 1:0.1 to1:1.5. When the equivalent of the catalyst is less than 0.1, a reactionmay not smoothly proceed. When the equivalent of the catalyst is greaterthan 1.5, a generation amount of reaction byproducts may increase.

Step (b) may include (b1) a step of filtering the product to obtain afiltrate; (b2) a step of separating the filtrate into an upper layer anda lower layer to remove the lower layer; (b3) a step ofvacuum-evaporating the upper layer to recover epicholorhydrin; and (b4)a step of filtering a product generated in step (b3).

In step (Ill), the catalyst and metal chloride salts generated fromepicholorhydrin may be removed. For example, when NaOH is used as acatalyst, NaCl may be removed through filtration. The filtration may beperformed using a metal filter net with a pore size of 1 to 100 μm,preferably, 10 to 30 _(I)lm.

In step (b2), the filtrate is injected into a separatory funnel,followed by being allowed to stand for 60 to 180 minutes withoutaddition of an organic solvent. As a result, the filtrate is separatedinto an upper layer and a lower layer. Since the product is present inthe upper layer, the lower layer, as a water-soluble layer, may beremoved. The present invention extracts a product without addition of anorganic solvent and a separate washing process, thereby beingecofriendly.

The vacuum evaporation of step (b3) may be performed at 100 to 120° C.to recover a volatile material. The evaporated and recoveredepicholorhydrin may be recycled.

In step (b4), filtration may be performed in the same manner as in step(b1) to remove a trace amount of remaining metal chloride salts.

Hereinafter, embodiments of the present invention will be described inmore detail. However, the following experimental results correspond torepresentative experimental results of the embodiments, and the scopeand content of the present invention should not be interpreted as beingreduced or limited by the embodiments and the like. The effects of eachof various embodiments of the invention, which are not explicitly setforth below, will be described in detail in a corresponding section.

The following experimental results show comparison results of theproperties and compositions of an epoxy reactive diluent preparedaccording to an embodiment of the present invention and an epoxyreactive diluent prepared according to a conventional method.

EXAMPLE

Cardanol (720 g, 1.0 eq) and epicholorhydrin (670 g, 3.0 eq) were fedinto a reactor, and 40% NaOH (337.7 g, 1.0 eq) was added theretodropwise for 90 minutes until a reaction temperature increased from 20°C. to 70° C. After completing the addition of NaOH, the reactants werefurther reacted for 2 hours while maintaining a reaction temperature ofthe reactants at 55 to 60° C., thereby obtaining a solution includingepoxidized cardanol. The solution was analyzed by gas chromatography(GC). As a result, the solution was analyzed to be constituted of 1.2%unreacted cardanol, 85.9% epoxidized cardanol, 4.2% 2-methyl-cardolglycidyl ether, 4.7% cardol-diglycidyl ether, and 3.6% dimer.

Next, the obtained solution was filtered to remove a sodium chloridesalt. The resultant filtrate was injected into a separatory funnel,followed by allowing layer separation to occur for 1 hour. A separatedlower layer was removed, and a separated upper layer was fed into areactor, followed by vacuum-evaporating at 120° C. to remove water andunreacted epicholorhydrin. The resultant concentrate was filtered toremove a sodium chloride salt, thereby obtaining an epoxy reactivediluent.

Comparative Example 1

Cardanol (720 g, 1.0 eq) and epicholorhydrin (670 g, 3.0 eq) were fedinto a reactor, and 40% NaOH (405 g, 1.2 eq) was added thereto dropwisefor 90 minutes until a reaction temperature increased from 50° C. to 90°C. After completing the addition of NaOH, the reactants were furtherreacted for 2 hours while maintaining a reaction temperature of thereactants at 60 to 65° C., thereby obtaining a solution includingepoxidized cardanol. The solution was analyzed by gas chromatography(GC). As a result, the solution was analyzed to be constituted of 1.4%unreacted cardanol, 81.8% epoxidized cardanol, 7.1% 2-methyl-cardolglycidyl ether, 6.8% cardol-diglycidyl ether, and 2.6% dimer.

Next, the obtained solution was filtered to remove a sodium chloridesalt. The resultant filtrate was injected into a separatory funnel,followed by allowing layer separation to occur for 1 hour. A separatedlower layer was removed, and a separated upper layer was fed into areactor, followed by vacuum-evaporating at 120° C. to remove water andunreacted epicholorhydrin. The resultant concentrate was filtered toremove a sodium chloride salt, thereby obtaining an epoxy reactivediluent.

Comparative Example 2

Cardanol (720 g, 1.0 eq) and epicholorhydrin (670 g, 3.0 eq) were fedinto a reactor, and 50% NaOH (347.4 g, 1.2 eq) was added theretodropwise for 90 minutes until a reaction temperature increased from 50°C. to 90° C. After completing the addition of NaOH, the reactants werefurther reacted for 2 hours while maintaining a reaction temperature ofthe reactants at 60 to 65° C., thereby obtaining a solution includingepoxidized cardanol. The solution was analyzed by gas chromatography(GC). As a result, the solution was analyzed to be constituted of 3.6%unreacted cardanol, 81.7% epoxidized cardanol, 6.9% 2-methyl-cardolglycidyl ether, 5.6% cardol-diglycidyl ether, and 2.2% dimer.

Next, the obtained solution was filtered to remove a sodium chloridesalt. The resultant filtrate was injected into a separatory funnel,followed by allowing layer separation to occur for 1 hour. A separatedlower layer was removed, and a separated upper layer was fed into areactor, followed by vacuum-evaporating at 120° C. to remove water andunreacted epicholorhydrin. The resultant concentrate was filtered toremove a sodium chloride salt, thereby obtaining an epoxy reactivediluent.

Comparative Example 3

Cardanol (720 g, 1.0 eq) and epicholorhydrin (670 g, 3.0 eq) were fedinto a reactor, and 30% NaOH (501.8 g, 1.2 eq) was added theretodropwise for 90 minutes until a reaction temperature increased from 50°C. to 90° C. After completing the addition of NaOH, the reactants werefurther reacted for 2 hours while maintaining a reaction temperature ofthe reactants at 60 to 65° C., thereby obtaining a solution includingepoxidized cardanol. The solution was analyzed by gas chromatography(GC). As a result, the solution was analyzed to be constituted of 3.9%unreacted cardanol, 80.7% epoxidized cardanol, 7.7% 2-methyl-cardolglycidyl ether, 5.9% cardol-diglycidyl ether, and 1.68% dimer.

Next, the obtained solution was filtered to remove a sodium chloridesalt. The resultant filtrate was injected into a separatory funnel,followed by allowing layer separation to occur for 1 hour. A separatedlower layer was removed, and a separated upper layer was fed into areactor, followed by vacuum-evaporating at 120° C. to remove water andunreacted epicholorhydrin. The resultant concentrate was filtered toremove a sodium chloride salt, thereby obtaining an epoxy reactivediluent.

Comparative Example 4

Cardanol (720 g, 1.0 eq), acetone (576 g, 0.8 part by weight based on 1part by weight of cardanol), and NaOH (96.5 g, 1.0 eq) were fed into areactor, and epicholorhydrin (401.7 g, 1.8 eq) was added thereto for 90minutes until a reaction temperature increased from 50° C. to 70° C.After completing the addition of epicholorhydrin, the reactants werefurther reacted for 2 hours while maintaining a reaction temperature ofthe reactants at 60 to 65° C., thereby obtaining a solution includingepoxidized cardanol. The solution was analyzed by gas chromatography(GC). As a result, the solution was analyzed to be constituted of 3.3%unreacted cardanol, 78.6% epoxidized cardanol, 2.9% 2-methyl-cardolglycidyl ether, 4.1% cardol-diglycidyl ether, and 11.1% dimer.

Next, the solution was vacuum-evaporated at 120° C. to remove acetoneand unreacted epicholorhydrin. The resultant concentrate was filtered toremove a sodium chloride salt, thereby obtaining an epoxy reactivediluent.

Comparative Example 5

Cardanol (720 g, 1.0 eq) and epicholorhydrin (670 g, 3.0 eq) were fedinto a reactor, and 50% potassium hydroxide (487.2 g, 1.2 eq) was addedthereto dropwise for 90 minutes until a reaction temperature increasedfrom 50° C. to 90° C. After completing the addition of potassiumhydroxide, the reactants were further reacted for 2 hours whilemaintaining a reaction temperature of the reactants at 60 to 65° C.,thereby obtaining a solution including epoxidized cardanol. The solutionwas analyzed by gas chromatography (GC). As a result, the solution wasanalyzed to be constituted of 4.8% unreacted cardanol, 76.5% epoxidizedcardanol, 9.8% 2- methyl-cardol glycidyl ether, 6.0% cardol-diglycidylether, and 3.6% dimer.

Next, the obtained solution was filtered to remove a sodium chloridesalt. The resultant filtrate was injected into a separatory funnel,followed by allowing layer separation to occur for 1 hour. A separatedlower layer was removed, and a separated upper layer was fed into areactor, followed by vacuum-evaporating at 120° C. to remove water andunreacted epicholorhydrin. The resultant concentrate was filtered toremove a sodium chloride salt, thereby obtaining an epoxy reactivediluent.

Next, the obtained solution was filtered to remove a potassium chloridesalt. The resultant filtrate was injected into a separatory funnel,followed by allowing layer separation to occur for 1 hour. A separatedlower layer was removed, and a separated upper layer was fed into areactor, followed by vacuum-evaporating at 120° C. to remove water andunreacted epicholorhydrin. The resultant concentrate was filtered toremove a potassium chloride salt, thereby obtaining an epoxy reactivediluent.

The epoxy reactive diluent prepared according to the example and aconventional epoxy reactive diluent product (NC-513, Cardolite) weresubjected to GC measurement and compared to each other. Results areshown in FIG. 6.

Referring to FIG. 6, it was confirmed that the diluent preparedaccording to the example exhibited high purity due to a high productcontent and low contents of unreacted cardanol and by-products, comparedto the conventional product.

The aforementioned description of the present invention is provided byway of example and those skilled in the art will understand that thepresent invention can be easily changed or modified into other specifiedforms without change or modification of the technical spirit oressential characteristics of the present invention. Therefore, it shouldbe understood that the aforementioned examples are only provided by wayof example and not provided to limit the present invention. For example,each of constituents described as a single form may be separatelyimplemented and, similarly, constituents described as being separatedmay be implemented in a combined form.

It should be understood that the scope of the present invention isdefined by the following claims and the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the invention as defined by the claims.

1. An epoxy reactive diluent, wherein a content of a compoundrepresented by Formula 1 below is 85% by weight or more based on a totalweight of an epoxy reactive diluent composition:

wherein n is 0, 2, 4 or
 6. 2. The epoxy reactive diluent according toclaim 1, wherein contents of cardanol, a compound represented by Formula2 below, a compound represented by Formula 3 below, and a compoundrepresented by Formula 4 below in the composition are respectively lessthan 2% by weight, less than 5% by weight, less than 5% by weight, andless than 4% by weight:

wherein Formulas 2 to 4, n is 0, 2, 4 or
 6. 3. The epoxy reactivediluent according to claim 1, wherein the composition has a viscosity of40 to 90 cps at 25° C.
 4. A method of preparing an epoxy reactivediluent, the method comprising: (a) a step of reacting a mixturecomprising cardanol and epicholorhydrin in a presence of a catalyst toobtain a product in which a content of epoxidized cardanol is 85% byweight or more; and (b) a step of isolating and purifying the product.5. The method according to claim 4, wherein the catalyst is a base. 6.The method according to claim 5, wherein the base is one selected fromthe group consisting of NaOH, KOH, Na₂CO₃, K₂CO₃, NaH and a combinationof two or more thereof.
 7. The method according to claim 5, wherein thebase is a 1 to 60% aqueous solution at a concentration.
 8. The methodaccording to claim 4, wherein, in step (a), the catalyst is addeddropwise to the mixture for 45 to 135 minutes, followed by allowing areaction to occur for 60 to 180 minutes.
 9. The method according toclaim 4, wherein, in step (a), an equivalent ratio of the cardanol tothe epicholorhydrin is 1:1 to 1:10.
 10. The method according to claim 4,wherein, in step (a), an equivalent ratio of the cardanol to thecatalyst is 1:0.1 to 1:1.5.
 11. The method according to claim 4, whereinstep (b) comprises: (b1) a step of filtering the product to obtain afiltrate; (b2) a step of separating the filtrate into an upper layer anda lower layer to remove the lower layer; (b3) a step ofvacuum-evaporating the upper layer to recover epicholorhydrin; and (b4)a step of filtering a product generated in the vacuum-evaporating. 12.The method according to claim 11, wherein, in step (b2), layerseparation is performed by allowing the filtrate to stand for 60 to 180minutes without addition of an organic solvent.
 13. The method accordingto claim 11, wherein, in step (b3), the vacuum-evaporating is performedat 100 to 120° C.